Amitriptyline & Nortriptyline

General Information

Amitriptyline is a tricyclic antidepressant drug that was first synthesized in 1960 and released for clinical use in 1961. The compound is administered either orally of by intramuscular injection in maintenance doses of up to 150 mg daily for outpatients or up to 300 mg daily for hospitalised patients. 

Amitriptyline is extensively metabolised to a series of more polar compounds, these include nortriptyline, a major plasma constituent which may be responsible for the antidepressant effects of its parent, and dinortriptyline which may be active and is found to a certain extent in plasma. Nortriptyline may be prescribed itself as an active antidepressant agent. 

The adverse effects of amitriptyline therapy include drowsiness, blurred vision, dry mouth, postural hypotension and dizziness. Amitriptyline has been found to impair skilled performance and to be additive with ethanol in its adverse effects. In overdose, patients may experience coma, seizures and cardiac abnormalities. 

Physostigamine, a cholinergic drug, has been used successfully in the diagnosis and antidotal therapy of poisoning with amitriptyline and other tricyclic antidepressants.